Quotes from Intergovernmental Panel on ClimateChange (Work in Progress!)IPCC AR4: Working Group I (The PhysicalScience Basis) Summary for Policymakers:‣"Warming of the climate system is unequivocal."‣"Most of the observed increase in globallyaveraged temperatures since the mid-20thcentury is very likely due to the observedincrease in anthropogenic greenhouse gasconcentrations."

Lowering CO 2 -emissionsLowering the carbon intensity of our society:‣ Switching from coal to gas‣ Improve energy efficiency‣ Extend use of renewable energy‣ Extend use of nuclear energyCarbon dioxide capture and storage (CCS) isvaluable addition to this portfolio:‣ Allows continued use of fossil energy sources in a carbonconstrained environment‣ Buys time for transition to sustainable energy systems

Challenges for CO 2 captureCaptureof CO 2 can be done withtechnologies presently available but:‣ Sizeable efficiency reduction‣ Power generation costs will increase‣ There is no experience with CO 2 captureintegrated at the power plant scale

Known issues with PCC‣ High cost: around $30/t CO 2 captured‣ Electricity cost increase from $30/MWh to$50/MWh for an 85% reduction in GHG‣ Loss of generation efficiency around 20-30% to capture 90% of CO 2‣ Not demonstrated in integrated powerplants scale‣ Sensitive to O 2 , SOx and other flue gasconstituents‣ Large increase in cooling water requirement